Re: [PATCH 1/3] i2c-piix4: Support alternative port selection register

[fetzerch <fetzer.ch@gmail.com>]

Hi Jean,

On 13.02.2016 22:51, Jean Delvare wrote:
> Hi Wolfram,
> 
> On Fri, 12 Feb 2016 20:27:20 +0100, Wolfram Sang wrote:
>> On Fri, Jan 29, 2016 at 10:44:52AM +0100, Jean Delvare wrote:
>>> The SB800 register reference guide says that the SMBus port selection
>>> bits may not always be in register Smbus0En (0x2c) but could
>>> alternatively be found in register Smbus0Sel (0x2e) depending on the
>>> settings in register Smbus0SelEn (0x2f.) Add support for this
>>> configuration.
>>
>> Were you able to test both cases?
> 
> I don't have the hardware myself so I was not able to test any case.
> I was hoping Christian would test. This is the reason why I am logging
> which register is used, so that we know if the alternative setting is
> ever used. I found the potential problem by looking at the datasheet,
> it's not something that has been reported (yet.)
> 
> Meanwhile I have found a datasheet for device 780Bh (named Bolton FCH
> on AMD's web site, but Hudson2 in our driver) which suggest that the
> "alternative" setting is the only possible one on this chipset. The
> register used to figure out the setting is marked as reserved. If the
> register exists still and the relevant bit is set, then my patch should
> work. If not then a better patch will be needed.
> 
> I'll try to gain access to a system with a Bolton FCH and experiment
> with it.
> 
> Then there's the most recent device, codenamed "CZ", for which I have
> no information at all.
> 

sorry for the late response. This time it slipped through on my side.

The sensors command still works fine without any noticable change.
Here is the output:

[1894808.057493] piix4_smbus 0000:00:14.0: SMBus Host Controller at
0xb00, revision 0
[1894808.057504] piix4_smbus 0000:00:14.0: Using register 0x2c for SMBus
port selection
[1894808.394960] i2c i2c-1: Found w83795adg rev. B at 0x2f
[1894808.666968] piix4_smbus 0000:00:14.0: Auxiliary SMBus Host
Controller at 0xb20

Thanks,
Christian